JPS60109141A - Manufacture of magnetron - Google Patents

Abstract

PURPOSE:To surely counterbalance the deformation of an antenna lead by forming the expanded section in the antenna lead in advance and by depressing the both sides of the lower end of this expanded section from its outside and seal- cutting it. CONSTITUTION:At the top of an antenna lead, an expanded section 24 wider than the rest of this antenna lead is formed in advance. At the final stage of the evacuation process, a cutter 22 is fitted on the lower end of the expanded section 24, depressing the both sides of an evacuation pipe 19 from outside. The constricted section of the evacuation pipe 19 first touches on the step-like portion of the expanded section 24 of the antenna lead 20, and, as the cutter 22 moves inward, the antenna lead 20 is pushed upward a little bit. Furthermore, as the cutter 22 is pressed in, the antenna lead 20 is depressed and then pushed downward. Therefore, when the position and the width demension of the expanded section are set in advance so that the deformations on both sides will be equal to each other, the main body of the antenna lead can be surely restored to its former position and shape before seal-cutting.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a magnetron, and more particularly to an improvement in a method for clamping and sealing an antenna lead in a metal exhaust pipe of an output portion thereof.

[Background technology and its problems]

For example, in the manufacturing method of magnetrons for electronic lenses, as shown in Figures 1 and 2, a manufacturing method that uses a metal exhaust pipe at the output section, passes the antenna lead through this, and vacuum-seals and cuts the exhaust pipe is widely used. <It has been implemented. In the figure, numeral 1 (r) is an anode cylinder, 12 is a plurality of anode vanes forming a cavity resonator, 13 is a cathode, 14 is a pole piece, 15 is an output fIll vacuum vessel wall, 16 is a sealing ring, 17 is a ceramic cylinder, 18 is an output sealed cylinder, 191fj is a copper exhaust pipe, 20 is a copper antenna lead, and 21 is an antenna lead through hole formed in the pole piece.

After assembling each part, the inside of the pipe is subjected to exhaust treatment, and as shown in FIG. A short circuit is made between the two terminals, and a vacuum seal is cut at the seal cut section A as shown in FIG. Then, the antenna cap 23 is press-fitted onto the outer periphery of the output part sealing sill 18 to complete the output part. Note that the metal exhaust pipe 19 and the sealed cylinder 18 constitute a choke girder for, for example, the second plane harmonic and the fourth high W1°4 wave.

By the way, according to such a manufacturing method, when the cutter cuts the seal, as the antenna lead is crushed, it is pushed down, albeit slightly, in the direction of the anode pane, as shown by arrow P in FIG. For example, if the antenna lead is a round bar with a diameter of 3 m, and the exhaust pipe has a diameter of 8 m and a wall thickness of 0.8 mm, the antenna +7-
It was confirmed that the size of the downward push of the do is approximately 0.5 mm. As a result, the four ends of the antenna lead were bent, causing the antenna lead to become bent. - At the through hole of the ruby, the distance S between the two becomes smaller than the predetermined dimension, and in extreme cases, there is a risk that the two may come into contact. If this interval becomes narrow or there are many variations in mass production, the high frequency coupling characteristics between the cavity resonator and the output section will deteriorate and the variations will increase. In addition, by predicting the amount of change in the antenna lead in advance, the antenna lead is assembled by shifting the position of the antenna lead in the opposite direction from the center of the hole with respect to the through hole of the pole piece, and when sealing and cutting, the antenna lead is deformed to the center of the hole. Although it is conceivable to design the antenna lead so that it gradually deforms, it is conceivable that the antenna lead will gradually deform due to the strain that remains in the antenna lead during long-term operation.

As described above, there is a disadvantage that it is difficult to obtain the desired output coupling characteristics. [Objective of the invention] This invention solves the above-mentioned inconveniences and provides a method for manufacturing a magnetron that prevents the antenna lead from being deformed and stuck due to the sealing cut 9 of the metal exhaust pipe. It is something to do.

[Summary of the invention]

In this invention, a widened portion is formed in advance directly above the position where the antenna reel inserted into the metal exhaust pipe is stopped and cut, and the lower end of this widened portion, that is, the cavity is also JIl′>i! :
÷Pinch the exhaust pipe from the outside with a cutter to seal it at the position corresponding to the stepped part, so that the antenna lead is pushed up a little by the widened part, and then cut it completely to seal it. This is a manufacturing method in which when the antenna lead is pressed down, the antenna lead returns to its original position and maintains its predetermined position, size, and shape.

[Embodiments of the invention]

An actual M1- example of the present invention will be explained below with reference to FIGS. 3 to 5. Note that the same parts as in FIGS. 1 and 2 are denoted by the same reference numerals, and the redundant numbers ijR and bright are omitted.

Therefore, a widened portion 24, which is wider than other portions, is formed in advance at the tip of the antenna lead.

As described above, this widened part 24 is formed just above the position of the sealing cut which has a predetermined size necessary for constructing a choke in the exhaust pipe. Crush and form.

Then, at the final stage of the exhaust process, the cutter 22 is applied to the lower end of the widened part, that is, the sealing cut position where the anode vane forming the cavity resonator coincides with the stepped part 24a, and the exhaust pipe is pinched and crushed from the outside. As a result, as shown in FIG.
Since this stepped portion is pushed up, θ is slightly pushed upward in the figure as indicated by arrow Po. Even cooler
As 22 is tightened, the antenna reat 20 is pinched and crushed, and at the same time, it is pushed downward as shown by arrow P.

By setting the position and width of the widened portion in advance so that the amount of deformation in both areas is the same, the main part of the antenna lead can be reliably returned to its position and shape before the sealing cut. .

Note that the antenna reel is not limited to being formed of a round bar, but may be a square bar, and the widened portion may be integrally formed at the tip thereof, or the widened portion may be formed by crushing the widened portion.

〔Effect of the invention〕

According to the magnetron manufacturing method of the present invention, when the antenna lead is sandwiched between metal exhaust pipes and sealed and cut, the deformation of the antenna lead can be reliably offset and the antenna lead can be set at a predetermined position and dimensional relationship. Deterioration of the local frequency coupling characteristics between the resonator and the output section can be suppressed. Moreover, it is possible to prevent the antenna lead from coming close to or welding the pole piece through which it passes, and it is possible to manufacture magnetrons with uniform output characteristics even in mass production.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of the main part showing state 4 before sealing by the conventional method, Fig. 2 is a longitudinal cross-sectional view illustrating the state after completion, and Fig. 3 is a sealing in an embodiment of the present invention. A vertical sectional view of the main part showing the state before cutting, Figure 4 is (4) - ( of Figure 3)
4), and FIG. 5 is an enlarged longitudinal sectional view of the main part showing the state during sealing cutting. 11... Anode cylinder, 12... Anode pane, 14...
- Pole piece, 19... Metal exhaust pipe, 20... Antenna lead, 22... Cutter, 24... Widening part, 24a... Step part. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 3

Claims (1)

[Claims] A part of the antenna lead extending from the cavity resonator is inserted into the metal exhaust pipe provided at the magnetron output part, and the exhaust pipe is pinched from the outside with a cutter to electrically connect the exhaust pipe and the antenna lead. In the magnetron manufacturing method for sealing and cutting, a widened portion is formed in advance on the antenna lead, and the cutter is used to crush the widened portion along the stepped portion on the −F cavity resonator side. , a method for manufacturing a magnetron characterized by sealing and cutting.